The study found that 52 percent of children ages 5 to 8 years old have had access to a mobile device while 39 percent of 2 to 4-year-olds and 10 percent of zero to 1-year-olds have had access

For years, media such as television and video game systems have been used as babysitters for younger children. But as technology advances and more gadgets are introduced, mobile devices like smartphones and tablets are being used for the same purposes.

Common Sense Media, a nonprofit group that focuses on the use of technology by children, prepared a study called "Zero to Eight: Children's Media Use in America." As the study suggests, it describes the amount of media children ages zero to eight consume via mobile devices and television.

The study looked at 1,384 parents with children up to 8 years old from May 27, 2011 to June 15, 2011.

Let’s start with television. According to the study, nine-month-olds spend almost an hour per day watching television or DVDs. Children under the age of two spend twice as much time watching TV and videos as they do reading books at 53 minutes and 23 minutes per day respectively. In addition, 30 percent of zero to 1-year-olds have a TV in their bedroom while 44 percent of 2 to 4-year-olds and 47 percent of 5 to 8-year-olds have a TV in their bedrooms as well.

As far as computers go, 53 percent of all 2 to 4-year-olds have used a computer and 90 percent of all 5 to 8-year-olds have used a computer. The average age of first use was around 3 and a half.

The newest group of gadgets to be introduced to youngsters is mobile devices like smartphones and tablets. According to the study, 29 percent of parents have downloaded apps specifically for their children on their phones. On average, 11 percent of the children used a cell phone or other mobile device for media consumption for about 43 minutes per day.

When it comes to both computers and mobile devices, the study notes that there is a "digital divide" among those in different income brackets. In the computer realm, 72 percent of children up to age 8 have a computer in their home. Among low-income families (less than $30,000 per year), this number is at about 48 percent where higher-income families (over $75,000 per year) are at 91 percent.

In addition to the digital divide is the "app gap," where 27 percent of lower-income families include a parent with a smartphone where 57 percent of higher-income families include a parent with a smartphone. Thirty-eight percent of lower-income parents don't even know what an app is where only 3 percent of higher-income parents are unaware.

Overall, the study found that 52 percent of children ages 5 to 8 years old have had access to a mobile device while 39 percent of 2 to 4-year-olds and 10 percent of zero to 1-year-olds have had access.